Serial port debugging: The inverter returns an 83 error packet
Symptom
In a project, the communication mode is Huawei inverter and Data collectors of other brands. The communication was normal before. After AC power is off, the inverter communication on a communication cable was abnormal. Multiple SUN2000-36KTL inverters on this bus return error code 83 after sending serial port packets.
Fault Locating
1. Packets are delivered on the communication bus. To shield the interference caused by cables, engineers need to send packets to a single SUN2000 at the local end. The fault symptom is the same：return 83 error.
2. Check whether packets have been sent to normal inverters and whether the response is normal. Returns error code 83 as the inverter communicates properly.
3. Measured the RS485 voltage on the user interface board. The RS485 resistance on the user interface board was normal. The customer reported that the RS485 resistance on the user interface board was not damaged.
4. Check the packets delivered by the customer. Inverter Modbus communication address 13, baud rate 9600, no verification, one stop bit. The customer delivers the message for reading the daily energy yield:
0D 03 7E 2C 00 01 5D 27, and the returned message: 0D 83 02 00 F2,
5. Daily energy yield occupies two bytes, but the number of bytes delivered by the customer is 1. Therefore, error code 83 is returned.
The correct packets to be sent are as follows:：0D 03 7E 2C 00 02 1D 26
